Use of a cyclone separator and climate chamber for hatching eggs and/or keeping poultry

ABSTRACT

The invention relates to the use of a cyclone separator for separating keratin particles originating from poultry out of a gas, in particular air. The separated particles comprise down particles. The invention furthermore relates to a climate chamber for hatching eggs and/or keeping poultry. Said climate chamber comprises a substantially closed compartment having two opposite side walls provided with one or more passages; as well as a substantially closed duct which extends outside the compartment and connects one of said side walls to the other of said side walls so as to form a substantially closed circuit together with the compartment. Said climate chamber furthermore comprises a cyclone separator, the inlet of which ends in the substantially closed duct and the outlet of which ends outside the closed duct for discharging into the environment.

The present invention relates to the field of young birds, in particularto the field of bird chicks.

Poultry, such as chickens, but also turkeys and other birds, arenowadays hatched and treated in hatcheries. This process starts with theeggs being hatched in a climate chamber. After the eggs have hatched,the young chicks may be reared in the climate chamber for some time,which may also be a different climate chamber than the one in which theeggs were hatched. Raising the chicks also takes place in otherchambers. Furthermore, the chicks are being subjected to operations,both manual operations in which individuals handle the chicks or crateswith chicks, and automated operations, such as the emptying of a cratecontaining chicks onto a conveyor belt, during which a large amount ofdust/down particles originating from the chicks is released in practice.

Hatching eggs and rearing the chicks is often carried out in a largehatchery or chick-rearing facility, that is to say a large buildinghaving several treatment chambers. A major problem which occurs in thisconnection is the transmission of microorganisms, such as bacteria,viruses and yeasts. Young chicks are carriers of microorganisms whicheasily spread amongst the animals and thus also to people working in thehatchery. Such microorganisms can be harmful to the (young) animals andhumans. For that reason, people working in a hatchery wear breathingmasks in order to prevent being infected by microorganisms. It is anobject of the present invention to combat the spread of microorganisms,such as bacteria, viruses and yeasts, in a poultry environmentcontaining young birds. The Applicant has found that a cyclone separatorcan be used for this purpose.

This object is achieved according to the invention by using a cycloneseparator for separating microorganisms out of a gas, in particular air.

The Applicant has found that the microorganisms, such as bacteria,viruses and yeasts, are spread by keratin particles which float in theair, or another gas, in the vicinity of the poultry. The keratinparticles act as carriers for the germs. By now removing these particlesfrom the gas, in particular air, the spread of microorganisms, such asbacteria, viruses and yeasts, can substantially be prevented.

The object according to the invention is thus achieved by using acyclone separator for separating keratin-comprising particlesoriginating from young birds out of a gas, in particular air.

A cyclone separator is generally known from the state of the art.Cyclone separators are used for separating particles out of a gas streamwhich have a relatively large density. The air is introduced into thecyclone chamber and made to rotate. Relatively heavy particles presentin the air are thus hurled outwards and come down the wall of thecyclone chamber to be collected in a reservoir. Gas from which theparticles have been removed is discharged from the center of the cyclonechamber, at the top of the cyclone.

The invention relates in particular to live poultry.

According to a further aspect, the invention relates to the use of acyclone separator in a hatchery for separating keratin-containingparticles originating from poultry out of a gas, in particular air.

When used according to the invention, the poultry comprises chicks, inparticular chicks younger than seven days. More particularly, the chicksare often younger than three days, such as one day or younger.

The keratin particles given off by young birds comprise in particulardown particles. Down particles are very light and therefore readilyfloat in a gas or air. Surprisingly, these very light down particles canbe separated from a gas stream in a very effective manner by means of acyclone separator. In practice, it has been found that the downparticles in question are those of a size <0.1 mm and even ≦0.05 mm.Even down particles having a size of ≦0.01 mm can readily be separatedout by means of such a cyclone separator, so that the spread ofmicroorganisms is substantially prevented.

Tests have shown that when a cyclone separator is used in a poultryenvironment, down particles having a size in the range of 0.01 mm to0.10 mm can be separated out very efficiently. However, smaller andlarger particles have also been found in the reservoir of the cycloneseparator during tests.

According to the invention, it is furthermore advantageous if, on theone hand, the poultry and any person treating the poultry who may bepresent and, on the other hand, the inlet and outlet of the cycloneseparator are in the same, substantially closed, chamber. Thus, air ispassed through the cyclone separator from said chamber and immediatelycirculated back into the chamber. The air quality in said chamber wasfound to have improved significantly without having to take many othermeasures, except arranging a cyclone separator in said chamber. This isbeneficial for the person/persons working with the chicks. In addition,this is also beneficial for the chicks since the spread ofmicroorganisms amongst chicks is thus prevented.

According to a further embodiment, the air to be discharged from aclimate chamber, such as a hatching machine, is passed through thecyclone separator. Particularly with such climate chambers, inparticular hatching machines, there are many bacteria in the air whichare being carried by down particles or other keratin particles. It istherefore highly effective to pass the air to be discharged from aclimate chamber through the cyclone separator.

According to a further use of the invention with a climate chamber, theclimate chamber is of the type which comprises:

-   -   a substantially closed compartment having two opposite side        walls provided with one or more passages;    -   a substantially closed duct which extends outside the        compartment and connects one of said side walls to the other of        said side walls so as to form a substantially closed circuit        together with the compartment;        in which the gas stream is circulated through the circuit;        in which a supply ends in the substantially closed duct so as to        supply air from the environment;        in which the inlet of the cyclone separator ends in the        substantially closed duct; and        in which the outlet of the cyclone separator ends outside the        closed duct for discharging into the environment.

Such a climate chamber is known from EP 1,104,987 and from applicationPCT/NL2007/050370 (application number) by the Applicant which was filedon Jul. 13, 2007.

In such a climate chamber, according to the invention, in particular atleast one of the opposite side walls is designed as a perforated plateprovided with a fluid line, through which said fluid is passed, in sucha manner that a side wall forms a heat exchanger by means of which thetemperature of the gas stream passing through said side wall can beinfluenced. Furthermore, according to the invention, in a climatechamber of this type, the compartment is advantageously subdivided intotwo or more subcompartments by at least one partition, with thepartition running parallel to the two opposite side walls, and thepartition being designed as a perforated plate provided with a fluidline, through which a fluid is passed, in such a manner that said sidewall forms a heat exchanger by means of which the temperature of the gasstream passing through said side wall can be influenced.

According to a further aspect, the invention relates to a climatechamber for hatching eggs and/or keeping poultry, comprising:

-   -   a substantially closed compartment having two opposite side        walls provided with one or more passages;    -   a substantially closed duct which extends outside the        compartment and connects one of said side walls to the other of        said side walls so as to form a substantially closed circuit        together with the compartment;    -   a gas displacement device incorporated in the substantially        closed duct for circulating a gas stream through the circuit;    -   a cyclone separator;        in which a supply ends in the substantially closed duct for        supplying air from the environment;        in which the inlet of the cyclone separator ends in the        substantially closed duct; and        in which the outlet of the cyclone separator ends outside the        closed duct for discharging into the environment.

In particular with such climate chambers, the air which is to bedischarged from such climate chambers contains many bacteria and germscarried on keratin particles, such as down particles. By passing the airto be discharged from the substantially closed duct through the cycloneseparator, these bacteria and germs are separated out of the airtogether with the keratin particles on which they are carried.

With the climate chamber according to the invention, it is particularlyadvantageous if one of the side walls, at least part thereof, isdesigned to be pivotable about a pivot axis in such a manner that saidpart can be pivoted open from the boundary surface of said compartmentdefined by the side wall into an open position in order to give accessto the duct; and if the cyclone separator is arranged in the duct, nearsaid pivotable side wall, that the cyclone separator is accessible fromthe compartment for cleaning purposes when said side wall is in an openposition. The cyclone separator is thus arranged in the climate chamber,namely in the duct, which connects one side of the compartment to theother side of the compartment for recirculating a gas stream, so thatthe cyclone separator does not take up any space outside the climatechamber. By providing the cyclone separator near a pivotable side wall,it becomes possible to approach the cyclone separator from thecompartment. Thus, every time the compartment is empty, the collectingreservoir of the cyclone separator can be emptied and the inside of thecyclone separator can be cleaned, if necessary. As such, it issufficient, in this case, if only a part of said side wall is pivotable.As the side wall is preferably designed as a perforated plate providedwith a fluid line, it is preferable if the entire side wall can bepivoted as one single part. Preferably, the pivot axis runs verticallyalong one side of the pivotable side wall.

According to a further embodiment, it is advantageous if the pivotableside wall is entirely inside the compartment in the open position and ifthe compartment, on the side of the side wall turned away from the pivotaxis, comprises a door for access to the compartment. Thus, the sidewall can be pivoted open in an inward direction of the compartment, asit were, towards the rear wall, so that it is possible to access thecyclone separator from the door side of the compartment in the duct.

According to a further embodiment of the climate chamber according tothe invention, the cyclone separator comprises:

-   -   a vertically arranged outer pipe having an inflow passage for        allowing gas into said outer pipe;    -   a vertical inner pipe inserted from above into the outer pipe        for allowing gas to stream from the inner pipe outward.

In this embodiment, it is furthermore advantageous if the bottom end ofthe inner pipe is lower than the inflow passage. With this embodiment,it is particularly advantageous if the internal diameter of the outerpipe, at the location of the inner pipe, is at most 35 cm, preferably atmost 30 cm, such as approximately 26 cm.

According to a further embodiment, the external diameter of the innerpipe is at most 17.5 cm, preferably at most 15 cm, such as approximately13 cm. The wall thickness of the inner pipe will usually be relativelysmall, such as smaller than 3 to 4 mm, so that the internal diameter ofthe inner pipe and the outer diameter of the inner pipe areapproximately equal.

According to yet a further aspect, the invention relates to an assemblyof two climate chambers according to the invention, in which eachclimate chamber comprises a rear wall which connects the side walls ofthe compartment to one another, and in which the rear walls of said twoclimate chambers are placed against one another back-to-back. In thismanner, a space-saving arrangement of several climate chambers is madepossible. This arrangement is possible according to the invention by thefact that a prior-art corridor between the rear walls of two climatechambers is now redundant. It is customary in the prior art to pass theair discharged from the climate chamber into this corridor, whichresults in down particles collecting on the floor in this corridor. Inorder to be able to remove these down particles, a person has to be ableto pass through said corridor, which means that this corridor has to beat least approximately 75 cm wide. Furthermore, cleaning the downparticles off the floor of the corridor is an unhealthy task for thestaff. This unhealthy task is now completely obsolete.

The present invention will be described in more detail below withreference to an example illustrated in the drawing, in which:

FIG. 1 shows a diagrammatic perspective view of a climate chamberaccording to the invention;

FIG. 2 shows a diagrammatic longitudinal section of the climate chamberfrom FIG. 1;

FIG. 3 shows a perspective view of an opened cyclone separator accordingto the invention and as used in FIGS. 1 and 2;

FIG. 4 shows a cross-sectional view of the closed cyclone separator fromFIG. 3, which cross-sectional view is taken at the location of theinlets;

FIG. 5 shows a diagrammatic, horizontal longitudinal section of a partof the climate chamber from FIGS. 1 and 2;

FIG. 6 shows a view similar to FIG. 5, but with one side wall of thecompartment pivoted open;

FIG. 7 shows a view similar to FIG. 6, but with the cyclone separatorpartially pivoted open;

FIG. 8 shows a view similar to FIG. 7, but with the cyclone separatorcompletely pivoted open; and

FIG. 9 shows a highly diagrammatic perspective view of a chambercontaining a cyclone separator according to the invention, as well aspoultry.

FIGS. 1 and 2 show a climate chamber 1 according to the invention. Saidclimate chamber 1 is delimited externally by two opposite side walls 4,6, a rear wall 3, an opposite front wall 8, a ceiling 5 and a floor 7.In order to be able to control the temperature inside the climatechamber as well as possible, said walls, floor and the ceiling willpreferably have been insulated.

The climate chamber comprises a compartment 2 through which climatizedair is passed, in order to be able to control the climatologicalconditions, such as temperature, atmospheric humidity and composition ofthe air, etc., in the compartment 2. The compartment 2 is delimited bytwo opposite side walls 11, 17, by a rear wall which is the same as therear wall 3 of the climate chamber, by a ceiling 28 and by a floor whichmay be the same as the floor 7 of the climate chamber. In this example,the compartment 2 is subdivided into four subcompartments 10, althoughfewer or more subcompartments 10 are also readily possible. Thesubcompartments 10 are in each case separated from one another by a heatexchanger 12. In addition, the side wall 11 is designed as a heatexchanger and, if desired, the side wall 17 may also be designed as aheat exchanger. The heat exchangers 11, 12 and possibly 17 may bedesigned in accordance with the description given in EP 1,104,987, inaccordance with the description given in application PCT/NL2007/050370(application number) filed by the Applicant on Jul. 13, 2007 orotherwise. The heat exchanger disclosed in EP 1,104,987 andPCT/NL2007/050370 essentially consists of a metal plate with a largenumber of perforations and fluid lines. In order to be able to influencethe temperature of said plate, a fluid, in particular water, at aspecific desired temperature is passed through the fluid lines, so thatthe plate is kept at or brought to a specific temperature.

The perforated plate is usually arranged vertically and a gas stream ispassed through the perforated plate which, if the plate is arrangedvertically, hits the plane of the plate at right angles, passes throughthe perforations and then flows out on the other side of the plate.While the gas stream is passing through the plate, the temperature ofthe gas stream can be influenced. If the temperature of the gas streamis to be raised, the plate will have a higher temperature than the gasstream or be brought to a higher temperature and if the temperature ofthe gas stream is to be lowered, the plate will have a lower temperaturethan the gas stream or be brought to a lower temperature. For a detaileddescription of an example of such a heat exchanger, reference is made tothe aforementioned publication EP 1,104,987 and PCT/NL2007/050370(application number) filed by the Applicant on Jul. 13, 2007.

As can be seen in FIG. 1, the subcompartments 10 can be accessed viadoors 29 provided in the front wall 8. Trolleys 24, 25 can be driveninto the compartments via the doors 29, which trolleys 24, 25 containeggs 27 to be hatched in the subcompartment 10 or chicks 26 to be rearedin the subcompartment 10. It will be clear that a different kind of dooris also possible. Thus, it is conceivable to provide one pivot doorwhich pivots about a horizontal hinge or a rolling door instead of fourdoors.

As can be seen in FIGS. 1 and 2, the space between the ceiling 28 of thecompartment 2 and the ceiling 5 of the climate chamber 1 is subdividedby a partition 14. One or more fans 15 (not shown in FIG. 1) areprovided in said partition 14. Said fan 15 can be driven by a motor 16in order to cause an air stream to circulate in accordance with thearrows in FIG. 2. On the left-hand side, the fan 15 sucks in air from areturn duct 23 and, via the ceiling 18 of the compartment 28, deliversit on the right-hand side to a chamber 22 which feeds the right-handcompartment 10. The air then enters the compartment 2 via theperforations in the heat exchanger 11, arrives in the firstsubcompartment 10 and horizontally flows through said firstsubcompartment, arrives in the second subcompartment 10 via heatexchanger 12 and horizontally flows through said second subcompartment10, arrives in the third subcompartment via the opposite heat exchanger12, horizontally flows through said third subcompartment andsubsequently arrives in the fourth subcompartment 10 again via theopposite heat exchanger 12.

Having flowed through the fourth subcompartment 10 horizontally, the airwill arrive in the return duct 23 via the side wall 17 which may, ifdesired, also be designed as a heat exchanger, or flow back to theintake side of the fan via the return duct. The return duct 23, thechamber 22 and the space between the ceiling 28 of the compartment andthe ceiling 5 of the climate chamber together form an (upside down)U-shaped duct. Together with the compartment 2, said U-shaped duct formsa circuit.

So as to be able to supply fresh air to this circuit of circulating gas,an air inlet 20 is provided comprising a valve (not shown) for allowingmore or less air to pass through, depending on the position of saidvalve. In order to be able to moisturize the air to be circulated in thecircuit, a spray nozzle 18 is provided. In order to be able to dischargeair from the circuit (for example when fresh air is supplied at 20), anair discharge 31 is provided.

According to the invention, said air discharge 31 is connected to theoutlet of a cyclone separator 30. The cyclone separator 30 is installedin the chamber 22 which is situated next to the (right-hand) side wall11 of the compartment. Said cyclone separator is indicated highlydiagrammatically in FIGS. 1 and 2 by reference numeral 30 and is shownin more detail in FIGS. 3 and 4.

FIG. 3 shows a perspective view of the interior of the rear half 40 andthe front half 41 of the cyclone separator 30. The rear half 40 isattached to the inside of the side wall 4 by the rear side which isturned away from the plane of the drawing. The cyclone separator 30 asillustrated in FIG. 3 is designed as a double cyclone separator, thuscomprising essentially two cyclone chambers 44 which have beenintegrated into a single unit. The cyclone separator 30 comprises twoouter tubes 33, each of which is provided with an inner tube 34 whichprojects inwards from the top end. Each of the outer tubes 33 isprovided with a conically tapering part 35 at the bottom which ends in acollecting box 32 in which the particles 24 separated out of the air inthe cyclone separator are collected. The top ends of the inner tube 34end in a common discharge chamber 42. Said discharge chamber 42 has anoutlet 43 which forms the inlet for a fan 38 which sucks in air in theaxial direction and discharges air in the radial direction. The fan 38is accommodated in a fan chamber 45 and is driven by a motor 46. Thedischarge 31 is connected to the fan chamber for discharging the gaswhich has been sucked in by the fan 38, such as air. Each cyclonechamber 44 is provided with a supply duct 37 for supplying gas, inparticular air, to the inlet openings 36 of the cyclone chambers 44.Each inlet opening 36 is situated, viewed in the horizontal direction,next to the respective inner tubes 34. The supply ducts 37 are providedtangentially with respect to the cyclone chambers in such a manner thatturbulence is immediately imparted to inflowing gas so that the latterswirls around the inner tube 34. When the fan 38 is switched on, it willwant to blow air out via the discharge 31 (or the relief valve 46 stillto be discussed in more detail), which results in air being sucked infrom the discharge chamber 42. This sucking action results in air beingsucked in via the supply ducts 37 and entering the outer tubes 33 viathe inlet openings 36. In each outer tube 33, the inflowing air will bebrought into a quick rotating flow around the associated inner tube 34.As a result of this quick rotating flow, particles 24 present in the airwill be hurled outward and subsequently fall down in order to becollected in particle receptacle 32 via the conical part 35. The airwhich has been cleaned of particles 24 is extracted through the outertubes 33 via the inner tubes 34.

When used in a climate chamber 1, a discharge valve (not shown) will beprovided in the discharge 31 in order to close off the discharge when itis not necessary to discharge any gas, such as air. Without additionalmeasures, this would mean that the cyclone separator would in fact notbe operational when the discharge valve is closed, as the fan cannotdischarge the gas. In that case, it would also be possible to switch offthe fan. However, in order to increase the effectiveness of the cycloneseparator 30 in such a climate chamber, the fan chamber 45 isfurthermore provided with a relief outlet 48 via which the gas cannevertheless still be discharged from the fan chamber 45. Said reliefoutlet 48 ends in the chamber where the cyclone separator is suspended.If the cyclone separator is fitted in the climate chamber 1, thischamber will be the chamber 22 (FIG. 2). A relief valve 47 may beprovided in the relief outlet 48 which opens automatically if apredetermined pressure is exceeded in the fan chamber. Thus, it ispossible to ensure by means of the relief valve 47 that the reliefoutlet 48 only opens when the discharge valve is closed.

As FIG. 3 shows, the rear half 40 and the front half 41 are connected toone another by means of hinges 39. The hinges 39 make it possible toopen the cyclone separator 30, for example for cleaning purposes. FIG. 3shows the cyclone separator 30 in the open position. FIG. 4 shows thecyclone separator in horizontal cross section, taken at the location ofthe supply ducts 37, and in the closed position.

FIG. 5 shows a horizontal cross section of the right-hand section of theclimate chamber 1 from FIGS. 1 and 2, with only the right-mostsubcompartment 10. At the top in FIG. 5, a further climate chamber 1 isillustrated by dotted lines, the back of the rear wall 9 of whichadjoins the back of the rear wall 9 of the other climate chamber.

FIGS. 6, 7 and 8 show views similar to that of FIG. 5, but the furtherclimate chamber which is placed back-to-back against the climate chamberis in this case omitted.

FIG. 6 shows that the (right-hand) side wall 11 of the compartment 2, inthis case a heat exchanger 11, can rotate into the subcompartment 10 bymeans of a vertical hinge 21 which is provided on the rear wall 9 of thecompartment/the climate chamber. Thus, it is possible to gain access tothe subcompartment 10 via the door 29 and pivot the side wall 11/heatexchanger 11 into the subcompartment 10, as illustrated in FIG. 6. Thusaccess is gained to the cyclone separator 30 which is situated in thechamber 22 and it is possible to remove and empty the particlereceptacle 32 (FIG. 2). In addition, the front part 41 of the cycloneseparator 30 can be pivoted open by the hinges 39, as is illustrated inFIG. 7. This pivoting movement can be continued until the completelypivoted open position as illustrated in FIG. 8 is reached. Thus, accessis also gained to the interior of the cyclone separator 30. In order tobe able to assess if the interior of the cyclone separator 30 is clean,it is advantageous according to the invention if the front part 41 ofthe cyclone separator is of transparent design, at least if the sectionof the outer tubes situated on the front part 41 is transparent. Whenthe cyclone separator has been cleaned, it can be pivoted closed again,following which the side wall 11 can be brought into the position shownin FIG. 5 again.

FIG. 9, finally, shows, by way of illustration, in a highly diagrammaticmanner yet another method of use according to the invention. FIG. 9shows a chamber, in particular a room, delimited by side walls. For thesake of clarity, the ceiling and the front side wall have been omittedin FIG. 9. The floor is denoted by reference numeral 50, two oppositeside walls are denoted by reference numerals 51 and 53 and the rear wallis denoted by reference numeral 52. A cyclone separator 30, as describedabove, is situated in this chamber 54 or in this room, respectively.Said cyclone separator 30 is fitted on the side wall 53 and the inlet ofthe cyclone separator 30 ends at 37 in the chamber 54. The outlet 31likewise ends in the chamber 54. Air which has been treated by thecyclone separator 30 does thus not leave the chamber 54, but isrecirculated in the chamber, as it were. A work station 55 with a crate56 containing chicks 26 thereon is situated in the chamber 54. A persondiagrammatically indicated by reference numeral 57 is also present inthe chamber 54 in order to submit the chicks 26 to an operation.

Both in the climate chamber as illustrated in the FIGS. 1, 2 and 5-8,and in the chamber as illustrated in FIG. 9, young birds, in particularyoung chicks, are present. Such chicks carry microorganisms, such asbacteria, viruses and yeasts, which are spread by means of keratinparticles which are given off by said young birds, in particular downparticles. By means of a cyclone separator 30, these down particles canbe separated out of the air passed through said cyclone separator 30.Together with these down particles, the bacteria and germs are separatedout of the air.

In the context of the present application, the term climate chamber isin particular intended to refer to a climate chamber for incubating eggsand/or a climate chamber for rearing chicks younger than four days oreven of between zero and one day old. With all these applications, it isimportant to be able to control the temperature very accurately as youngchicks are not able to regulate their own body temperature very wellyet. In order to raise them under optimum conditions, it is important,particularly during the initial phase after hatching (birth), to keepthese animals at a predetermined temperature which depends on the animaland to control this temperature very accurately. The term climatechamber according to the invention is understood to mean in particular adevice having an internal chamber (the compartment) which is able tocontrol the temperature inside and within the entire internal chamberwith an accuracy of ±3° C., preferably with an accuracy of ±1° C. oreven more accurately (the term accuracy is in this applicationunderstood to mean that the greatest temperature difference between anytwo locations in said chamber—the compartment—is at most said accuracy,i.e. at an accuracy of ±1° C., the temperature difference will thereforebe at most 2° C.). In this case, a climate chamber with insulated wallsis used, inside which a specific desired climatized environment ismaintained.

The invention claimed is:
 1. A method for separating particlescomprising down particles from air, the method comprising: (a) supplyingair from the environment to a substantially closed duct; (b) introducingthe air from the substantially closed duct to a substantially closedcompartment comprising chicks younger than 7 days, wherein thesubstantially closed duct and the substantially closed compartment forma substantially closed circuit; (c) introducing the air from thesubstantially closed circuit to an inlet of a cyclone separator, whereinthe cyclone separator comprises a first outlet which ends outside thesubstantially closed duct for directly discharging air into theenvironment, and a second outlet which ends inside the substantiallyclosed duct; (d) returning a portion of the air to the substantiallyclosed duct through the second outlet of the cyclone separator andcirculating the air through the substantially closed compartment; and(e) discharging a portion of the air directly from the cyclone separatorto the environment through the first outlet.
 2. The method as claimed inclaim 1, wherein the chicks are younger than 3 days.
 3. The method asclaimed in claim 1, wherein the chicks are 1 day old or younger.
 4. Themethod as claimed in claim 3, wherein the down particles have a size of≦0.1 mm.
 5. The method as claimed in claim 1, wherein the particlescomprise down particles having a size in the range of 0.01 to 0.10 mm.6. The method as claimed in claim 1, wherein the chicks and the inletand the second outlet of the cyclone separator are situated in achamber.
 7. The method as claimed in claim 6, in which the entirecyclone separator is situated in said chamber.
 8. The method as claimedin claim 1, wherein gas is discharged from a climate chamber.
 9. Themethod as claimed in claim 1, wherein the substantially closedcompartment comprises a hatching machine.
 10. The method as claimed inclaim 1, wherein the substantially closed compartment comprises twoopposite side walls provided with one or more passages; thesubstantially closed duct which extends outside the substantially closedcompartment and connects one of said side walls to the other of saidside walls so as to form the substantially closed circuit together withthe substantially closed compartment; wherein gas is circulated throughthe substantially closed circuit; a supply ends in the substantiallyclosed duct so as to supply air from the environment; the inlet of thecyclone separator ends in the substantially closed duct; and the firstoutlet of the cyclone separator ends outside the substantially closedduct for discharging into the environment.
 11. The method as claimed inclaim 10, wherein at least one of the opposite side walls is aperforated plate provided with a fluid line, through which a fluid ispassed, wherein said side wall forms a heat exchanger by whereby thetemperature of the gas passing through said side wall can be influenced.12. The method as claimed in claim 10, wherein the compartment issubdivided into two or more subcompartments by at least one partition,with the partition running parallel to the two opposite side walls,wherein the partition is a perforated plate provided with a fluid line,through which a fluid is passed, in such a manner that said side wallforms a heat exchanger whereby the temperature of the gas passingthrough said side wall can be influenced.